Production of acetone from acetaldehyde



Patented Aug. 21, 1934 PRODUCTION OF ACETONE FROM ACETALDEHYDE Lloyd Swallen, 'Terre Haute, Ind, assignor to C oration, Terra Hallie, Ind, a corporation of Maryland Commercial. Solvents No Drawing.

My invention relates to a process of obtaining acetone from acetaldehyde. More particularly, my invention relates to a process of obtaining acetone from acetaldehyde at elevated temperatures and, preferably, reduced pressures in the presence of appropriate catalysts.

In the past, acetone has generally been obtained commercially by one or the other of two extensively used' methods. In the dry distillation of hard woods, pyroligneous acid, containing among other substances, acetic acid, is obtained. Calcium acetate obtained by the neutralization .of this acid is converted in turn, into acetone by dry distillation. More recently large quantities of acetone have been obtained as a by -product in the product-ion of n-butyl alcohol by fermenting carbohydrates. Both of these processes present cer tain disadvantages from a commercial viewpoint which need not be presented here.

In co-pending applications, U. i5". Serial No."

310,906, filed October 6, 1928-and U. S. Serial No. 364,318, filed May 18, 1929 have been described processes of obtaining ketonesfrom alcohols. I have now found that a process somewhat similar to those described in the aforementioned appli-. cations may likewise be applied to the preparation of acetone from acetaldehyde. In carrying out my new process acetaldehyde is subjected to the action of elevated temperatures, preferably in the presence of catalysts. Examples of my preferred method'of carying out this new reaction Will be described below. i

Suitable catalysts for effecting the conversion of acetaldehyde to acetone at elevated temperatures may be selected from a wide range of materials. Among those which have been found to be .enicac'ious for this purpose are the oxygen compounds of metals of the third and fourth periods of the periodic system, as for example, oxygen compounds of iron, manganese, copper and other heavy metals (that is to say, iron oxide, oxidized iron, manganic hydroxide, copper hyadroxide, copper carbonate, etc). Also, metals, as for example, irony'haine been found capable of producing the reaction. Also substances or mixtures containing such substances, as for example, ferruginous minerals, may be employed advantageously.

The efficiency of catalysts of the above nientinned character may be considerably in r d by the use of auxiliary substances furthering the reaction, as for example, oxygen compounds of alkaline earth metals, including magnesium, such as calcium carbonate, calcium oxide, magnesium oxide and the like.

Application January 9, 1930, Serial No. 419,750

24 sl- 260F134) :P'ATET :iice

One of the most efficient catalysts which" jhave tried'is of the character disclosed in United tates Patents Nos. 1,625,924, 1,625,925, 1,625,926, 1,625,: 927, 1,625,928 and 1,625,929, issued April 26, 19-27, for use in the production of synthetic methanol. These catalysts initially comprise a plurality of difl'ic-ulty reducible metal oxides, a plurality of easily reducible metal oxides, and a metallic halide, as -for example, zinc oxide, iron oxide and zinc chloride.

The following examples are illustrative of these catalysts: I

' Exampl .I

.8 kilo rams ofchromi nitrate (GMNOB) 381 20 and-1,5 kilogram o nickel n tra e iNidiOhafiIiiQ) are dissolved in ite s of water. and to this solution there i a ded ho-thes retinal amount (5,4 tors of 112.175 n rmal); o ammonium hydroxide .10 precipitate chromium hydroxide and nickel hydrate. then centrifuged to recover precipitated hydrates and the resultant precipitate is thorough washed with water, dried, and broken up into granules.

v Egrcmiple I I 3900 g ams zinc nitrate Z N-Oa 2.6li20 and Example Hi 2600 grams of zinc nitrate (ZmNCg) 3.51120) ,and 160 grams of tungstic oxide (W003) are mixed and heated until the zinc nitrate is converted to zinc oxide. The resultant yellow mass is-powdered and mixed with 40.0 grams of 510% zinc bromide solution. The resultant mass is dried and broken up into granules.

7 Example IV 2250 grams of cobalt nitrate v(Co (NOsMfiHzO) are dissolved in 259 liters of water and the solution is heated to C. There 'is then added 7.5 kilograms of zinc oxide .after which the solution is vigorously stirred and sufficient ammonium thydroxide is added to precipitate the cobalt as .00- balt hydrate. The precipitated mass is recovered by .de'cantation and filtration, is washed, dried,

The solution is then moistened with a solution containing 1480 grams zinc chloride and dried once more.

Example V 2600 grams of zinc oxide in powdered form are mixed by thorough sifting with 500 grams of black copper oxide. The resultant mixture is moistened with an aqueous solution containing 150 grams cuprous chloride and 200 grams of dextrin. The resultant mass is dried and broken, up into pieces whereupon it is ready for use.

Example VI the sol Lion has cooled 10 grams zinc chloride and 96fgrams ferric nitrate are added. To the resulting cold solution 100 grams zinc oxide are then added with constant stirring. The 'resulting wet mass is heated in a porcelainevaporating dish to dryness and then placed in a copper crucible in which it is heated overfa Fletcher burner to drive off the nitrogen peroxide fumes. The material thus obtained is crushed sufficiently to pass a 65- mesh screen and to it 8.2 grams zinc chloride dissolved in 600. 0. water are added. The product thus obtained hardens spontaneously and is olive green in color.

Below will be found a description of the composition and method of preparing a number of catalysts other than those of the abovetype, which have been found to be suitable for use in my new process. It is distinctly understood, however, that these examples as well as those listed above are cited merely as illustrative of the character of the catalyst mixtures which I prefer to use and that I am in no way bound to the use of the examples cited. Many other combinations may also be satisfactorily employed in my process.

- Example VII grams chromium nitrate 40 grams calcium acetate 96 grams ammonium carbonate Example VIII grams ferric nitrate 100 grams calcium acetate v2 liters water Precipitated with: grams anhydrous potassium carbonate 500 c. 0. water i The procedure is the same as that described under ExampleI except that after filtering the precipitate as dry as possible, it is workedup with about two liters of distilled water until free from lumps; warmed for about half an hour at 509-60" (3.; then filtered and washed as usual.

. Example IX 61 grams cupric nitrate 64 grams magnesium nitrate 2 liters water Precipitated with: i

450 c. c. of 10% sodium hydroxide solution.

-,with the acetaldehyde being treated.

found that in carrying out my new process it is The procedure outlined under Example I is then followed.

When acetaldehyde is passed at elevated temperature over suitable catalysts such as, for example, those. described above, acetone is obtained together with certain other products, the character of which varies considerably, depending upon the presence or absence of other materials I have not necessary that the acetaldehyde be absolutely pure. Other substances which do not react with the acetaldehyde or the acetone, or

grams chromium nitrate (CNNOBMQHZO) I which do not react toform substances reacting are diss -ved with heating in 60 c. 0. water. After in turn with these two compounds, may be present with the acetaldehyde without producing appreciably harmfuleffects. In some cases, as will be seen hereafter, the presence of such materials may even produce beneficial results.

. The presence of diluents with materials being subjected to catalytic treatment has frequently been shown to have beneficial efiects. In some cases, this is due to a reduction in the partial pressure of the material being treated. In other cases, thediluent may be of such a character as to inhibit or. lessen the tendency for the material under treatment to decompose or to form condensation or polymerization products. .In still other. cases, the diluent may serve as what may be termed a beneficial poison. In studying: various types of catalytic reactions investigators have reported that the presence of certain additional materials act as partial poisons of the catalyst being employed in that they tend to, prevent the catalyst from also accelerating secondary reactions of an undesirable character. Such a condition is found to be thecase with acetaldehyde. At elevated temperatures and in the presenceof certain catalysts, acetaldehyde is decomposed as follows:

onscnoacmoo It has been found that thepresence of1certain diluent materials gives what may be termed a protective influence on the acetaldehyde and prevents the decomposition of the character pointed out above. Apparently secondary reactions of this character require, a. larger energy of. activation as a result of strong preferential adsorption onthe catalyst surface. Under ordinarygiconditions acetaldehyde at 350 C, and in the presence of, say, iron, is partly resinified and partly decomposed into carbon monoxide and methane. With other catalysts a similar reaction takesplace at somewhat different temperatures.

It appears also that the catalytic conversion of acetaldehyde to acetone is carried out with somewhat better results at' pressures appreciably lower than atmospheric than at ordinary pressures. conditions of the reaction may .serve to lower the. partial pressure of the acetaldehyde being reacted, and thus accomplishthe same result as if the reactions had actually been carried out under a-partial vacuum. The same efiect is brought: about: by the use of diluent materials which act as protective or beneficial poisons.

The particular pressure to be employed in the conversion of 'acetaldehyde to acetone depends to a large extent upon the economic considerations involved in the particular operation. For example, the pressure employed will depend upon the rate at which the aldehyde is conducted'i'over the catalyst, the-volume of the catalyst,

the character of the catalyst used, the reaction ,3-

Materials substantially inert underthe temperature, cost of raw materials, method of recovering the unconverted acetaldehyde and the acetone formed during the reaction, and finally, the method adopted for attaining reduced pressure.

I may employ any of a number of methods of conducting the aoetaldehyde over the catalyst under reduced pressure. Thesemethod-s. are equally satisfactory from the point of yicw of the efiicacy of the reaction and the particular one adopted for use will depend upon the facili ties ayailable to the operator or theparticular needs of a certain I may, for example, create a partial vacuum in the reaction chamber and introduce the acetaldehyde to be reacted at such a rate as to maintain the desired reduced pressure in the reaction zone. The acetone thus formed and-the unconverted acetaldeiiyde are continually removed and recovered byv any convenient tmethodsuc-h as by condensing or by any suitable adsorption or solvent recovery process.

Another convenient method of attaining-the desired reduced pressure is by mixing the .acetaldehyde with a material inert under the conditions of the reaction, in sufli'cient quantity to reduce the partial pressure of the acetaldehyde, to the desired degree. .Mat'erials which I have found to be especially suitable for this purpose are, for example, carbon dioxide gas, nitrogen, hydrogen, carbon anon-oxide, methane, or the gaseous products formed during the reaction. In case it is desired to employ the vapors of an inert liquid compound as the :means of obtaining the desired reduced pressure or of preventing the undesirable decomposition reactions, it is highly advisable that the material chosen the miscible with acetald'ehyde and, preferably, easily vaporized. The mixture of acetaldehyde "vapor and vapor of the inert material may :be passed directly over the heated catalyst. More accurately regulated of :acetaldehyde vapor and inert vaporresulting in more accurately regulated partial pressure of the :acetaldehydemay be obtained by yaporizingthe acetaidehydeland inert material in diii erent vessels and later mixing the desired quantities of vapors of the-two substances. When an uncondensibie gas or a material .in which the acetone is not soluble is employed as the means of reducing the partial pressure of the acetaldehyde being treated or when the :reacifion carried out at reduced pressure without the aid of :a diluent material such as has :been emimerated, it is usually necessary to pass the gases issuing from the reaction charm her through a scrubbing or solvent recovery system of some kind for the purpose of recovering the acetone;

A convenient and economical method of attaining the desired "reduced pressures is by using as the inert diluent the gaseous reaction produms formed in the process. The required proportion of these gaseous products, after the removal of'the acetone, unconverted aoetaldehyde and any other condensible product that may be formed by side reaction, .by condensation, scrubbing or other suitable method, and supplemented by additional -inert material, if necessary, is mixed width aceta'ldehyde wapor and again passed over the catalyst. In this way, the process may be carried out in a cyclic the required partialxpressure of the acetaldehydeibeing maintained by purging :at intervals or continuously, a portion of the gaseous reaction products, or,

v if necessary, makmg additions of gaseous material irom auxiliary i source, of supply: The mass action effect of these gaseous reaction products employed as diluents is app rently small since the conversion of, acetaldehyde to acetone only slightly reduced by their use.-

. After .a number ofdays use the catalyst begins to lose its eiiiciency and the rate of conversion of acetaldehyde-to acetone decreases appreciably.

I have found, howeyer, that the original efficiency of the catalyst may beeasilyand quickly restored. :When the rate of conversion has decreased to .a point beyond which the operation oi theprocess is not economical, the operation may be stopped and the catalyst reactivated by passing, over it oxygen or oxygen containing gas such asair, for a number of hours at tempera.- tures of about 450-600 C.

u The table given :below shows experimental reobtained under different operating condi-' On basisoitwomolsof acetaldehydeggivingone :mol of acetone.

The examples above .are cited merely tor the purpose of illustrating the yaried conditions under which new process may be satisfactorily operated and fit distinctly understood thatll am not limited by. any of the conditions therein stated. I v

reactions may be carried out over a :fairly wide range of temperatures, say. from about .390 C. to about 59 6. ."I prefer, however, :to employ temperatures ranging from about 400 to about 500 C. factor, of course, may be varied considerably depending upon the other factors as nature of catalyst, rate of flow of acetaldehyde vapor, pressure employed, meth- 0d of attaining the desired pressure, .etc.

The at which the reaction is efiected may also be varied over .a wide range provided is mamtailned. appreciably below atmospheric pressure, the percentage of aoetaldehyde ZCQII- verted into acetone being increased as the pressure is decreased. 1 preter, however, to make use oripresmires ranging from about 25 mm. to about 300 mm. (mercury). It is understood, of course, that in this nor-inaction I :use the terms pressure and reduced pressure as meaning also partial pressure" in case the desired reduced pressure of the acetaldehyde "is attained bythe use of an inert diluent instead oi by the use of vacuum. I claim generally the process of .efiec'ting the herein described process atrouse of carbondioxide'or nitrogengases for this purpose. 1

I have found that my new process may be satisfactorily carried out by'the aid of afairly wide variety of catalysts and. while I prefer to employ catalysts of the character described in this specification, it is distinctly understoodthat I do not confine myself to the use of only such methods.

Now having described my invention, what I claim as newand novel is: f

1. A process for the production of acetone which comprises subjecting to the action of cata lysts comprising essentially oxygen compounds of metalsof the third period of the periodic table at temperatures from 300 C. to 650 C.'a gaseous mixture in which acetaldehyde vapor'isthe only reactant present in substantial concentration and in which the pressure of said acetaldehyde vapor is substantially lower than atmospheric pressure.

2. A process for the production of acetone which comprises subjecting to the action of catalysts comprising essentially oxygen compounds of metals of the third period of the periodic table, at temperatures from 300 C. to 650 C., a gaseous mixture in which acetaldehyde vapor is the only reactant present in substantial concentration.

3. A process for the production of acetone. which comprises subjecting to the action of catalysts comprising essentially oxygen compounds of metals of the third period of the periodic table at a temperature of about 400 C. a gaseous mixture in which acetaldehyde vapor is the only reactant present in substantial concentration.

4. A process for the production of acetone which comprises subjecting to the action of catalysts comprising. essentially oxygen compounds of metals of the third period of the periodic table at a'temperature' of about 400 C. a gaseous mixture in which acetaldehydevapor is the only reactant present insubstantial concentration and in which the pressure of said acetaldehyde vapor is between mm. and 300 mm. of mercury.

5. A process for the production of acetone which comprises subjecting to :the action of catalysts comprising essentially oxygen compounds of metals of the third period-of the periodic table andof an auxiliary substancepromoting the activity of the catalyst selected from the group consisting of oxygen compounds of alkaline earth metals and magnesium, at temperatures from 300 C. to 650 C., a gaseous mixture in'which acetaldehyde vapor is the only reactant present in substantial concentration. I

. 6. 'A process for, the production of acetone which comprises subjecting to the' action of catalysts comprising essentially oxygen compounds of metals of the third period of the periodic table and of an auxiliary substance promoting the activity of the catalyst selected from the group consisting of oxygen compounds of alkaline earth metals" and magnesium, at temperatures from 300C. to 650 C., a gaseous mixture in which acetaldehyde vapor is the only reactant present in substantial concentration. and inwhich the pressure of said acetaldehyde vapor is substantiallylower than atmospheric pressure.

'7. A process forthe production of acetone which comprises subjecting to the action of catalysts essentially comprising (initially) a plurality of diflicultly reducible metal oxides, a plurality of easily reducible metal oxides, and a metal halide, at temperatures from 300 C. to 650 C., a gaseous mixture in which acetaldehyde vapor is the only reactant present in substantial concentration; I

8. A process for the production of acetone which comprises subjecting to the action of catalysts essentially comprising (initially) a plurality of difiicultly reducible metal oxides, a plurality of easily reducible metal oxides and a metal halide, at temperatures from 300 C. to 650 C., a gaseous mixture in which acetaldehyde vapor is the only reactant present in substantial concentration and in which the pressure of said acetaldehyde vapor is substantially lower than atmospheric pressure.

9. A process for the production of acetone which comprises subjecting to the action of catalysts essentially comprising (initially) a difficultly reducible metaloxide, an easily reducible metal oxide and ametal halide, at temperatures from 300 C. to 650 0., a gaseous mixture in which acetaldehyde vapor is the only reactant present in substantial concentration, and in which the pressure of said acetaldehyde vapor has been reduced to pressures substantially below atmospheric pressure by diluting said acetaldehyde vapor with gaseous materials inert under the 'conditio'ns of the reaction.

10. A process as claimed in claim 9 in which the acetaldehyde vapor is diluted with sufiicient nitrogen gas to give the required reduction in the pressure of the acetaldehyde vapor.

'11. A process as claimed in claim 9-in which the acetaldehyde vapor is' diluted with sufficient carbon dioxide gas to give the required reduction and pressure of the acetaldehyde vapor.

12. A process as claimed in claim 9 in which the acetaldehyde vapor is diluted with a sumcient amount of the gaseous products previously formed in the reaction to give the required reduction and pressure of the acetaldehyde vapor.

13. A process for'the production of acetone which comprises subjecting substantially pure acetaldehyde vapor to the action of catalysts essentially comprising (initially) a difiicultly reducible metal oxide, an easily reducible metal oxide anda metal halide at temperatures from 300 C. to 650C. 314. A process ,for the production of acetone which comprises subjecting. substantially pure acetaldehyde vapor to the action of catalysts essentially "comprising (initially) a difiicultly reducible metal oxide, an easily reducible metal oxide and a metal halide at temperatures from 300 C. to 650 C. and at pressures substantially lower than atmospheric pressure.

15. A process for the production of acetone which. comprises subjecting substantially pure acetaldehydevapor to the action of catalysts comprising essentially oxygen compounds of metals of the third period of the periodic table at temperatures from 300C. to 650 C. and at pressures substantially lower than atmospheric pressure.

16. A process for the production of acetone which comprises subjecting substantially pure acetaldehyde vapor to the action of catalysts comprising essentially oxygen compounds of metals of the thirdperiod of the periodic table and of an auxiliary substance promoting the aceasily reducible metal oxides, and a metal halide, at temperatures from 300 C. to 650 C. and at pressures substantially lower than atmospheric pressure.

18. A process for the production of acetone which comprises subjecting to the action of catalysts comprising essentially oxygen compounds of metals selected from the group consisting of iron, copper and manganese at temperatures from 300 C. to 650 C. a gaseous mixture in which acetaldehyde vapor is the only reactant present in substantial concentrations and in which the pressure of said acetaldehyde vapor is substantially lower than atmospheric pressure.

19. A process for the production of acetone which comprises subjecting to the action of catalysts comprising initially essentially zinc oxide, iron oxide and zinc chloride, at temperatures from 300 C. to 650 C. a gaseous mixture in which acetaldehyde vapor is the only reactant present in substantial concentration and in which the pressure of said acetaldehyde vapor is substantially lower than atmospheric pressure.

20. A process for the production of acetone which comprises subjecting to the action of catalysts chosen from the group consisting of catalysts essentially comprising oxygen compounds of metals of the third period of the periodic table and catalytic masses essentially comprising (initially) a difiicultly reducible metal oxide, an easily reducible metal oxide and a metal halide at temperatures from 300 C. to 650 0;, a gaseous mixture in which acetaldehyde vapor is the only reactant present in substantial concentration and in which the pressure of said acetaldehyde vapor is substantially lower than atmospheric pressure.

21. A process for the production of acetone which comprises subjecting to the action of catalysts chosen from the group consisting of catalysts essentially comprising oxygen compounds of metals of the third period of the periodic table and catalytic masses essentially comprising (initially) a difficultly reducible metal oxide, an easily reducible metal oxide and a metal halide at temperatures from 300 C. to 650 0., a gas consisting of acetaldehyde vapor.

22. A process for the production of acetone which comprises subjecting to the action of catalysts chosen from the group consisting of catalysts essentially comprising oxygen compounds of metals of the third period of the periodic table and catalytic masses essentially comprising (initially) a diflicultly reducible metal oxide, an easily reducible metal oxide and a metal halide at temperatures from 300 C. to 650 (3., a gas consisting of acetaldehyde vapor, the pressure of said acetaldehyde vapor being substantially lower than atmospheric.

23. In a catalytic process for the production of acetone from gas mixture containing acetaldehyde vapor as a major component, the improvement which comprises subjecting the gaseous reactant mixture, at temperatures from 300 C. to 650 C., to the action of a catalyst essentially comprising (initially) a mixture of easily-reducible and diflicultly-reducible metal oxides and a metal halide.

24. In a catalytic process for the production of acetone from gas mixtures containing acetaldehyde vapor as a major component, the improvement which comprises subjecting the gaseous reactant mixture, at temperatures from 300 C. to 650 0., to the action of a catalyst essentially comprising (initially) a mixture of chromium oxide, iron oxide, zinc oxide and zinc chloride.

LLOYD C. SWAILEN.

Certificate of Correction Patent No. 1,970,782. August 21, 1934. LLOYD C. SWALLEN It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 94, strike out the formula and insert instead (Zn (NO .6H O) page 2, line 116, for the right-hand portion of the formula CH CO read CH CO; and that the said Letters Patent should be read With these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 2d day of October, A. D. 1934.

[SEAL] LESLIE FRAZER,

Acting Commissioner of Patents. 

